Pipe connector

ABSTRACT

An apparatus for connecting two pipes in fluid communication includes a connector body having opposing open ends, with each open end configured for receiving a free end of a pipe, and a mechanical interlock arrangement for preventing or limiting axial movement of the connector body relative to a free end of a pipe when the free end of the pipe is received in an open end of the connector body. A mechanical seal arrangement provides a metal-to-metal seal between a pipe inserted into one of the open ends and the connector body.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/361,633, filed Mar. 22, 2019, pending, which is a continuation ofU.S. patent application Ser. No. 14/432,955, filed Apr. 1, 2015, nowU.S. Pat. No. 10,253,908, issued Apr. 9, 2019, which is the U.S.national phase of PCT International Patent Application No.PCT/GB2014/052748, filed Sep. 10, 2014, which claims the benefit ofGreat Britain Patent Application No. 1316077.5, filed Sep. 10, 2013,Great Britain Patent Application No. 1319292.7, filed Oct. 31, 2013,Great Britain Patent Application No. 1405658.4, filed Mar. 28, 2014,Great Britain Patent Application No. 1408085.7 filed May 7, 2014, andU.S. patent application Ser. No. 14/303,164, filed Jun. 12, 2014, theentire contents of each of which are hereby incorporated by reference inthis application.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

(NOT APPLICABLE)

FIELD OF THE INVENTION

The present invention relates to an apparatus, an assembly and a methodfor connecting two pipes in fluid communication, e.g. two oil pipes.

BACKGROUND OF THE INVENTION

There is an ongoing requirement within the oil industry to provide costefficient and consistent methods of connecting oil pipes together in away that minimises the risk of oil leakage.

Typically, flanged joints are used. These have a number ofdisadvantages. For example, flanged joints are vulnerable and can becompromised by uneven bolt tightening. Moreover, rubber seals aregenerally used within these joints, and often fail due to thermaldegradation, as well as being at significant risk of damage andsubsequent failure from bad practice when joints are assembled on site.

Flanged joints also require welding. This is time consuming duringassembly, increasing down time for pipe repairs as well as presenting afire risk. Further, amidst recent proposals for better offshore pipelineregulation and more refined safety rules covering repairs, there is arequirement to employ qualified welders to perform any repairs, which isa considerable added expense. The installation of flange joints alsorequires very high precision, requiring highly skilled labour forassembly, further increasing the cost of repairs.

BRIEF SUMMARY OF THE INVENTION

A first aspect of the invention provides an apparatus for connecting twopipes in fluid communication, the apparatus comprising a connector bodyhaving opposing open ends, each open end configured for receiving a freeend of a pipe; a mechanical interlock arrangement, for preventing orlimiting axial movement of the connector body relative to a free end ofa pipe; and a mechanical seal arrangement for providing a metal-to-metalseal between a pipe inserted into one of said open ends and theconnector body.

In normal use, the assembly serves to provide the two pipes in fluidcommunication and prevents undesired separation of the pipes. Themechanical interlock arrangement advantageously locks all the componentstogether to limit axial movement, without the use of flanges or thecomponents having to be welded together. The metal-to-metal seal isprovided to act between an internal surface of the connector body and apipe received in an open end of the connector body. It will beunderstood that a seal is required between each pipe and the connectorbody. The metal-on-metal arrangement provides a very strong seal,suitable for withstanding high pressures and high temperatures. A metalseal also has a high resistance to corrosion, increasing the life of theseal, especially when compared to traditional seals, such as rubber orasbestos O-rings or gaskets.

In exemplary embodiments, the mechanical seal arrangement includes ametallic element configured to fit on a free end of a pipe, and to bereceived in one end of the connector body. In exemplary embodiments, themetallic element is specifically dimensioned to fit on a pipe to ensurethe mechanical seal arrangement can create a strong seal, in combinationwith the connector body. In exemplary embodiments, the geometry of themetallic element ensures that the metallic element maintainsconcentricity with the pipe when being compressed in use.

In exemplary embodiments, the metallic element is an olive having atapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the connector body. In exemplaryembodiments, the two angled surfaces have slightly different angles. Inuse, the olive surface abuts the connector body surface, forming a verystrong seal.

In exemplary embodiments, the apparatus further includes a capconfigured to fit over an open end of the connector body. In exemplaryembodiments, the cap is used for applying a force to the metallicelement, in order to assure a seal between a pipe and the connectorbody.

In exemplary embodiments, the cap is a nut, configured to receive anopen end of the connector body.

In exemplary embodiments, the cap substantially covers an end of theconnector body, in normal use. In exemplary embodiments, one end of thecap is configured to receive the free end of a pipe, e.g. with a verysmall degree of clearance.

In exemplary embodiments, the connector body comprises a stop, arrangedto limit the movement of the cap in an axial direction with regards tothe connector body.

In exemplary embodiments, the stop projects radially from an externalsurface of the connector body.

In alternative embodiments, the connector body has a planar internalsurface. Advantageously, this can substantially limit, in use, the riskof the fluid within a pipe coming into contact with the mechanical lockarrangement.

In exemplary embodiments, the stop is a surface perpendicular to thelongitudinal axis of the connector body.

In exemplary embodiments, the mechanical seal arrangement furthercomprises a resilient washer arranged for sustaining the force appliedby the cap on the metallic element. In exemplary embodiments, the washeris intended to account for any variation in the force applied by the cap(e.g. a reduction in applied force as the bolts, or another appropriatemethod of applying force, loosen over time) to ensure that a strong sealis maintained between the mechanical seal arrangement and the connectorbody.

In exemplary embodiments, the washer is configured to be located betweenthe cap and the metallic element. Advantageously, the washer protectsthe metallic element from damage, such as abrasion that might otherwiseoccur if the cap contacted the olive.

In exemplary embodiments, the connector body has a planar internalsurface.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one circumferential groove on an internal surface of theconnector body. In such embodiments, the groove is intended foralignment with a corresponding groove on the external surface of thepipe to be inserted into the connector, in order to define a bore orchannel between the connector body and the pipe, for receiving a lockingelement, e.g. a length of wire, in order to resist against separation ofthe pipe and connector body.

In exemplary embodiments, the cap has a circumferential groove on aninternal surface, and the connector body has a circumferential groove onan external surface. In normal use, the groove on the cap lines up withthe groove on the connector body, defining a bore or channel between thecap and the connector body, for receiving a locking element, e.g. as alength of wire, in order to resist against separation of the cap andconnector body.

In alternative embodiments, the cap has a threaded portion on aninternal surface at one end of the cap and the connector body has athreaded portion on an external surface. In use, the threaded portionsengage one another, to enable to cap to be screwed onto the connectorbody and limit axial movement of the cap relative to the connector body.In exemplary embodiments, a circumferential groove is provided on aninternal surface at the other end of the cap. In use, the groove on thecap lines up with a corresponding groove on a pipe received in theconnector body, so as to define a bore or channel between the cap andthe pipe, for receiving a locking element, e.g. as a length of wire.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, e.g. for locating in a bore or channelformed between the connector body and a pipe received therein, orbetween a bore or channel formed between the cap and a pipe received inthe connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, for locating in at least one of the grooveson the internal surface of the cap, and a threaded arrangement betweenthe cap and connector body for preventing or limiting axial movement ofthe connector body relative to the cap.

In exemplary embodiments, the mechanical interlock arrangement comprisesa groove on an outside surface of at least one pipe and a projection onan internal surface of the connector body, configured such that theprojection engages with the groove to prevent or limit axial movement ofthe connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, such that they can be brought together aroundthe pipes, in use.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

Advantageously, installation of the apparatus is simplified, as thefirst and second parts of the connector body can be brought together ina transverse direction around the remaining components of the apparatus.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to eachother.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

A second aspect of the invention provides a pipe assembly connecting twopipes in fluid communication, the assembly comprising two pipes, eachhaving a free end; a connector body having opposing open ends, each openend being dimensioned to receive the free end of one of the pipes; and amechanical seal arrangement located at each open end of the connectorbody, for providing a metal-to-metal seal between each pipe and theconnector body.

In exemplary embodiments, all components can advantageously be suppliedas one assembled unit. This can provide cost savings in terms ofmanufacture as well as transportation to site. It also greatlysimplifies the installation process, as relatively little needs to bedone on site to install the assembly, compared to existing methods.

In exemplary embodiments, each pipe comprises at least onecircumferential groove on an outer surface, and the mechanical sealarrangement comprises at least one circumferential groove on an internalsurface, such that the grooves on the pipe and the mechanical sealarrangement line up, defining at least one bore or channel within thepipe assembly.

In exemplary embodiments, wire is located within each channel to limitthe movement of the mechanical seal arrangement relative to the pipe.

In exemplary embodiments, movement of the connector body relative to themechanical seal arrangement is limited by a threaded arrangement.

In exemplary embodiments, the connector body comprises a shoulder,projecting radially inwardly from an internal surface of the connectorbody, arranged to limit the movement of the pipes in an axial directionwith regards to the connector body.

In exemplary embodiments, the shoulder projects radially inwardly to anextent such that the internal diameter of the shoulder is substantiallyequal to the internal diameter of the pipes.

In exemplary embodiments, each pipe comprises at least onecircumferential groove on an outer surface, and the connector bodycomprises a plurality of circumferential grooves on an internal surface,such that grooves on the pipe and the connector body line up, definingat least one bore or channel within the pipe assembly, for receiving ina locking element.

In exemplary embodiments, each mechanical seal arrangement comprises ametallic element configured to locate on the free end of one of saidpipes, and contact the connector body, creating a seal.

In exemplary embodiments, the metallic element is an olive having atapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the connector body.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element upon application        of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

In exemplary embodiments, the assembly further comprises a cap arrangedto locate on the free end of the pipe and apply a force to the metallicelement.

In exemplary embodiments, the cap is configured to substantially coverthe free end of the pipe and the metallic element.

In exemplary embodiments, the assembly further comprises a resilientwasher, located between the cap and the metallic element, to assure theforce applied by the cap on the metallic element in use.

In exemplary embodiments, the connector body comprises a shoulder,projecting radially inwardly from an internal surface of the connectorbody. Insertion of the free end of each pipe is limited by the internalshoulder, such that the connecting body can be repeatably located in thecorrect place relative to the pipes.

In exemplary embodiments, the internal diameter of the shoulder issubstantially equal to the internal diameter of the pipes. Thisminimises the amount of turbulence within the fluid flow, furtherreducing the risk of leakage and increasing the efficiency within thepipe.

In exemplary embodiments, each pipe comprises at least onecircumferential groove on an outer surface, and the connector bodycomprises a plurality of circumferential grooves on an internal surface,such that grooves on the pipe and the connector body line up, definingat least one channel within the pipe assembly. In exemplary embodiments,as the internal shoulder of the connecting body consistently locates thepipes in a correct position relative to the connecting body, thecorresponding grooves line up, creating channels within the pipeassembly.

In alternative embodiments, an entire internal surface of the connectormay be planar, with no internal shoulder.

In exemplary embodiments, an internal surface of the cap is providedwith at least one groove. In exemplary embodiments, an external surfaceof each pipe includes at least one corresponding groove. In use, thegroove on the cap aligns with the groove on the pipe, to define a boreor channel for receiving a locking element (e.g. a length of wire) forresisting axial separation of the cap and pipe. In exemplaryembodiments, each groove on the pipe is provided at a location spacedfrom the free end of the pipe. In such embodiments, in use, when lockingwires have been inserted into the channels, this greatly reduces therisk of the fluid within the pipe coming into contact with the lockingwires, which is undesirable.

In those embodiments where the wire is threaded between each cap and thepipe, a threaded connection is provided between the cap and theconnector body, by means of which the cap is screwed onto the connectorbody.

In exemplary embodiments, the mechanical interlock arrangement comprisesa groove on an outside surface of at least one pipe and a projection onan internal surface of the connector body, configured such that theprojection engages with the groove to prevent or limit axial movement ofthe connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, such that they can be brought together aroundthe pipes, in use.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

Advantageously, installation of the apparatus is simplified, as thefirst and second parts of the connector body can be brought together ina transverse direction around the remaining components of the apparatus.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to eachother.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

A third aspect of the invention provides a method of connecting twopipes in fluid communication, the method comprising providing two pipes,each pipe having a free end; locating a metal-to-metal seal element onthe free end of each pipe; and locating each free end of the pipe withina connector body, such that the connector body bridges the two pipes;wherein the metal-to-metal seal elements provide a metal-to-metal sealbetween a respective pipe and the connector body.

Advantageously, the method of connecting the two pipes is very simpleand easily repeatable, meaning that minimal training is required toperform the method. Also, in the case of pipe repairs, downtime isgreatly reduced compared to current methods, minimising the cost of anyrepairs. Moreover, the method avoids the need for flanges used commonlyfor coupling two pipes together in fluid communication.

In exemplary embodiments, the method comprises the step of providing acap configured to locate on the free end of each pipe, wherein the capis configured to receive an open end of the connector body and applyinga force to the metallic element, in order to assure a seal between thepipe and the connector body.

In exemplary embodiments, the method also comprises the step ofproviding a mechanical interlock arrangement, for preventing or limitingaxial movement of the connector body relative to the pipes.

In exemplary embodiments, the method further comprises forming acircumferential groove on an outside surface of at least one pipe, andlining up the circumferential groove with at least one of a plurality ofcircumferential grooves on an internal surface of the connector body, inorder to define at least one channel.

In alternative embodiments, the method further comprises forming atleast one circumferential groove on an outside surface of at least onepipe, and lining up the circumferential groove with at least one of aplurality of circumferential grooves on an internal surface of the cap,in order to define at least one channel.

In exemplary embodiments, the method further comprises threading alength of wire through the at least one channel, in order to prevent orlimit axial movement of the connector body relative to the free ends ofthe pipes.

In those embodiments where the wire is threaded between each cap and thepipe, a threaded connection is provided between the cap and theconnector body, by means of which the cap is screwed onto the connectorbody.

In exemplary embodiments, the mechanical interlock arrangement comprisesforming a groove on an outside surface of at least one pipe andproviding a projection on an internal surface of the connector body, andengaging the projection with the groove to prevent or limit axialmovement of the connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, the method further comprises providing aresilient washer between the cap and the seal element, for applying aforce to the seal element.

In exemplary embodiments, the mechanical seal arrangement also includesa threaded portion on an internal surface and the connector bodyincludes a threaded portion on an outside surface, and the methodincludes engaging the threaded portions in order to prevent or limitaxial movement of the connector body relative to the mechanical sealarrangement.

In exemplary embodiments, the mechanical seal arrangement also includesa circumferential groove, which defines a channel in combination with acircumferential groove on an outside surface of the connector body, anda length of wire is threaded through the channel in order to prevent orlimit axial movement of the mechanical seal arrangement relative to theconnector body.

A further aspect of the invention provides a coupling arrangement forconnecting a pipe to a further pipe or a connector, the couplingarrangement comprising a connector body having a mechanical engagementarrangement for preventing or limiting axial movement of the connectorbody relative to a free end of the pipe; and a mechanical sealarrangement for providing a metal-to-metal seal between the pipe and theconnector body.

In exemplary embodiments, the mechanical seal arrangement includes afirst metallic element configured to fit on a free end of a pipe.

In exemplary embodiments, the first metallic element is specificallydimensioned to fit on a pipe to ensure the mechanical seal arrangementcan create a strong seal, in combination with the connector body.

In exemplary embodiments, the mechanical seal arrangement furtherincludes a second metallic element, configured to be located between thefirst metallic element and an internal surface of the connector body,such that the seal is created between the first and second metallicelements.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element or pipe upon        application of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion. In exemplaryembodiments, the contact portion is configured to project radiallyinward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially partcircular in cross-section. In exemplary embodiments, the profile of theintermediate portion is at least in part concave in cross-section. Inexemplary embodiments, the intermediate portion is tapered towards thecontact portion. In exemplary embodiments, the seal element is metallic.

In exemplary embodiments, the metallic element is an olive having atapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the connector body. In exemplaryembodiments, the two angled surfaces have slightly different angles. Inuse, the olive surface abuts the connector body surface, forming a verystrong seal.

In exemplary embodiments, the second metallic element is a sleeve,configured to encircle the free end of the pipe in use. In exemplaryembodiments, the sleeve is configured to bridge the free ends of thepipes in use.

In exemplary embodiments the coupling arrangement further comprises amechanism for applying a force to the first metallic element, in orderto assure a seal between a pipe and the connector body.

In exemplary embodiments, the connector body comprises one or moreapertures defining a plurality of channels or bores through a portion ofthe connector body, from a front surface of the connector body to aradial internal surface, the radial internal surface being locatedsubstantially adjacent the first metallic element in use.

In exemplary embodiments, each channel or bore comprises an internalthread such that a bolt, with a corresponding external thread, can berotatably inserted into each channel to provide a force that acts on thefirst metallic element in an axial direction.

In exemplary embodiments, the mechanical engagement arrangementcomprises at least one projection or barb on an internal surface of theconnector body.

In exemplary embodiments, the barb is circumferential.

In exemplary embodiments, the barb is tapered.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, such that they can be brought together aroundthe pipe, in use.

In exemplary embodiments, the outer profile of the connector body issubstantially square in cross-section.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

In exemplary embodiments, the mechanical interlock arrangement comprisesa groove on an outside surface of at least one pipe and a projection onan internal surface of the connector body, configured such that theprojection engages with the groove to prevent or limit axial movement ofthe connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one circumferential groove on an internal surface of theconnector body. In such embodiments, the groove is intended foralignment with a corresponding groove on the external surface of thepipe to be inserted into the connector, in order to define a bore orchannel between the connector body and the pipe, for receiving a lockingelement, e.g. a length of wire, in order to resist against separation ofthe pipe and connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, e.g. for locating in a bore or channelformed between the connector body and a pipe received therein.

Advantageously, installation of the apparatus is simplified, as thefirst and second parts of the connector body can be brought together ina transverse direction around the remaining components of the apparatus.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to oneanother.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

A further aspect of the invention provides an annular seal element forsealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element or pipe upon        application of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially partcircular in cross-section.

In exemplary embodiments, the profile of the intermediate portion is atleast in part concave in cross-section.

In exemplary embodiments, the intermediate portion is tapered towardsthe contact portion.

In exemplary embodiments, the seal element is metallic.

A further aspect of the invention provides an apparatus for connectingtwo pipes in fluid communication, the apparatus comprising a connectorbody having opposing open ends, each open end configured for receiving afree end of a pipe; a mechanical interlock arrangement, for preventingor limiting axial movement of the connector body relative to a free endof a pipe; and a mechanical seal arrangement for providing ametal-to-metal seal with the connector body.

The metal-to-metal seal is provided between an internal surface of theconnector body and a pipe received in an open end of the connector body,in use. The metal on metal arrangement provides a very strong seal,suitable for withstanding high pressures and high temperatures. A metalseal also has a high resistance to corrosion, increasing the life of theseal, especially when compared to traditional seals, such as rubber orasbestos O-rings or gaskets. The mechanical interlock arrangementadvantageously locks all the components together to limit axialmovement, without the use of flanges or the components having to bewelded together.

In exemplary embodiments, the mechanical seal arrangement includes ametallic element configured to fit on a free end of a pipe, and to bereceived in one end of the connector body. In exemplary embodiments, themetallic element is specifically dimensioned to fit on a pipe to ensurethe mechanical seal arrangement can create a strong seal, in combinationwith the connector body. In exemplary embodiments, the geometry of themetallic element ensures that the metallic element maintainsconcentricity with the pipe when being compressed in use.

In exemplary embodiments, the metallic element is an olive having atapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the connector body. In exemplaryembodiments, the two angled surfaces have slightly different angles. Inuse, the surfaces come into contact and the olive surface abuts theconnector body surface, forming a very strong seal.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element upon application        of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially circularin cross-section. In exemplary embodiments, the profile of theintermediate portion is concave in cross-section. In exemplaryembodiments, the intermediate portion is tapered towards the contactportion. In exemplary embodiments, the seal element is metallic.

In exemplary embodiments, the mechanical seal arrangement furtherincludes a cap, configured for applying a force to the metallic elementin use.

In exemplary embodiments, the cap is a nut, configured to receive anopen end of the connector body.

In exemplary embodiments, the connector body comprises a stop, arrangedto limit the movement of the nut in an axially inward direction withregards to the connector body, such that, in use, the nut substantiallycovers an end of the connector body.

In exemplary embodiments, the mechanical seal arrangement furthercomprises a resilient washer arranged for sustaining the force appliedby the cap on the metallic element. In exemplary embodiments, the washeraccounts for any variation in the force applied by the cap (e.g. areduction in applied force as the bolts, or another appropriate methodof applying force, loosen over time) to ensure that a strong seal ismaintained between the mechanical seal arrangement and the connectorbody.

In exemplary embodiments, the washer is configured to be located betweenthe cap and the metallic element. In exemplary embodiments, in use, thewasher advantageously protects the metallic element from damage, such asabrasion that would occur if the tightening means contacted the olive.

In exemplary embodiments, the connector body has at least onecircumferential groove on an internal surface.

In exemplary embodiments, the cap has a circumferential groove on aninternal surface, and the connector body has a circumferential groove onan external surface, and the groove on the cap lines up with the grooveon the connector body in use, defining a channel between the cap and theconnector body.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, such that they can be brought together aroundthe pipes, in use.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

Advantageously, installation of the apparatus is simplified, as thefirst and second parts of the connector body can be brought together ina transverse direction around the remaining components of the apparatus.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to eachother.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, for locating in one of the groove on theinternal surface of the connector body or the channel defined betweenthe cap and the connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesa groove on an outside surface of at least one pipe and a projection onan internal surface of the connector body, configured such that theprojection engages with the groove to prevent or limit axial movement ofthe connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

A further aspect of the invention provides a pipe assembly connectingtwo pipes in fluid communication comprising two pipes, each having afree end; a connector body having opposing open ends, each open endbeing dimensioned to receive the free end of one of the pipes; and amechanical seal arrangement located at each open end of the connectorbody, for providing a metal-to-metal seal with the connector body.

In exemplary embodiments, all components can advantageously be suppliedas one assembled unit. This can provide cost savings in terms ofmanufacture as well as transportation to site. It also greatlysimplifies the installation process, as relatively little needs to bedone on site to install the assembly, compared to existing methods.

In exemplary embodiments, the connector body comprises a shoulder,projecting radially inwardly from an internal surface of the connectorbody, arranged to limit the movement of the pipes in an axially inwarddirection with regards to the connector body. In exemplary embodiments,the free end of each pipe is limited by the internal shoulder, such thatthe connecting body is consistently located in the correct placerelative to the pipes.

In exemplary embodiments, the shoulder extends around the internalsurface of the sleeve circumferentially, and projects radially inwardlyuntil the internal diameter of the shoulder is substantially equal tothe internal diameter of the pipes. In exemplary embodiments, thisminimises the amount of turbulence within the fluid flow, furtherreducing the risk of leakage and increasing the efficiency within thepipe.

In exemplary embodiments, each pipe comprises at least onecircumferential groove on an outer surface, and the connector bodycomprises a plurality of circumferential grooves on an internal surface,such that grooves on the pipe and the connector body line-up, definingat least one channel within the pipe assembly. In exemplary embodiments,as the internal shoulder of the connecting body consistently locates thepipes in a correct position relative to the connecting body, thecorresponding grooves line up, creating channels within the pipeassembly.

In exemplary embodiments, the mechanical interlock arrangement comprisesa groove on an outside surface of at least one pipe and a projection onan internal surface of the connector body, configured such that theprojection engages with the groove to prevent or limit axial movement ofthe connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, each mechanical seal arrangement comprises ametallic element configured to locate on the free end of one of saidpipes, and contact the connector body, creating a seal.

In exemplary embodiments, the metallic element is an olive having atapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the connector body.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element upon application        of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially circularin cross-section. In exemplary embodiments, the profile of theintermediate portion is concave in cross-section. In exemplaryembodiments, the intermediate portion is tapered towards the contactportion. In exemplary embodiments, the seal element is metallic.

In exemplary embodiments, each mechanical seal arrangement furthercomprises a cap arranged to locate on the free end of the pipe and applya force to the metallic element.

In exemplary embodiments, the cap substantially covers the free end ofthe pipe and the metallic element.

In exemplary embodiments, each mechanical seal arrangement furthercomprises a resilient washer, located between the cap and the metallicelement, to ensure the force applied by the cap on the metallic elementis sustained in use.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, such that they can be brought together aroundthe pipes, in use.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

Advantageously, installation of the apparatus is simplified, as thefirst and second parts of the connector body can be brought together ina transverse direction around the remaining components of the apparatus.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to eachother.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

A further aspect of the invention provides a method of connecting twopipes in fluid communication, comprising providing two pipes, each pipehaving a free end; locating a mechanical seal arrangement for creating ametal-to-metal seal on the free end of each pipe; and locating each freeend of the pipe within a connector body, such that the connector bodybridges the two pipes; wherein the mechanical seal arrangement isconfigured to provide a metal-to-metal seal with the connector body.

In exemplary embodiments, the assembly method of connecting the twopipes is very simple and easily repeatable, meaning minimal training istherefore required to perform the method. Also, in the case of piperepairs, downtime is greatly reduced compared to current methods,minimising the cost of any repairs.

In exemplary embodiments, the method further comprises providing amechanical interlock arrangement, for preventing or limiting axialmovement of the connector body relative to the free ends of the pipes.

In exemplary embodiments, the method further comprises forming acircumferential groove on an outside surface of at least one pipe, andlining up the circumferential groove with at least one of a plurality ofcircumferential grooves on an internal surface of the connector body, inorder to define at least one channel.

In exemplary embodiments, the method further comprises threading alength of wire through the at least one channel, in order to prevent orlimit axial movement of the connector body relative to the free ends ofthe pipes.

In exemplary embodiments, the mechanical seal arrangement also includesa circumferential groove, which defines a channel in combination with acircumferential groove on an outside surface of the connector body, andwherein a length of wire is threaded through the channel in order toprevent or limit axial movement of the mechanical seal arrangementrelative to the connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesforming a groove on an outside surface of at least one pipe andproviding a projection on an internal surface of the connector body, andengaging the projection with the groove to prevent or limit axialmovement of the connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, the method further comprises applying a forceto the mechanical seal arrangement to strengthen the metal-on-metalseal.

A further aspect of the invention provides an apparatus for connectingtwo pipes in fluid communication, the apparatus comprising a connectorbody configured for bridging a first and a second pipe, each pipe havinga free end; a mechanical interlock arrangement, for preventing orlimiting axial movement of the connector body relative to the free endsof the first and second pipes; and a mechanical seal arrangement forproviding a metal-to-metal seal between the pipes and the connectorbody.

In normal use, the assembly serves to provide the two pipes in fluidcommunication and prevents undesired separation of the pipes. Themechanical interlock arrangement advantageously locks all the componentstogether to limit axial movement, without the use of flanges or thecomponents having to be welded together.

In exemplary embodiments, the metal-to-metal seal acts between aninternal surface of the connector body and the pipes bridged by theconnector body. It will be understood that a seal is required betweeneach pipe and the connector body. A metal-on-metal arrangement providesa very strong seal, suitable for withstanding high pressures and hightemperatures. A metal seal also has a high resistance to corrosion,increasing the life of the seal, especially when compared to traditionalseals, such as rubber or asbestos O-rings or gaskets.

In exemplary embodiments, the mechanical seal arrangement includes afirst metallic element configured to fit on a free end of a first pipe.In exemplary embodiments, the first metallic element is specificallydimensioned to fit on a pipe, for ensuring that the mechanical sealarrangement can create a strong seal, in combination with the connectorbody. In exemplary embodiments, the geometry of the first metallicelement ensures that the first metallic element maintains concentricitywith the pipe in use.

In exemplary embodiments, the mechanical seal arrangement includes asecond metallic element, configured to be located between the firstmetallic element and an internal surface of the connector body. As such,a seal is created between the first and second metallic elements.

Advantageously, the mechanical seal arrangement is housed generallywithin the connector body. This greatly decreases the risk ofcatastrophic failure of the apparatus (e.g. a large blow out). If acomponent fails, there will simply be leakage of the fluid within theassembly, e.g. along a tortuous path. In most cases, it is believed thatthis could be easily detected, so that the problem can be attended to assoon as possible.

In exemplary embodiments, the first metallic element is an olive havinga tapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the second metallic element. Inexemplary embodiments, the second metallic element is a sleeve,configured to encircle the two free ends of the pipes, in use. Inexemplary embodiments, the sleeve is configured to bridge the free endsof the pipes in use. In exemplary embodiments, the two angled surfaceshave different angles. In use, the olive surface abuts the sleevesurface, forming a very strong seal.

In alternative embodiments, the sleeve is integral with the connectorbody, such that, in use, the seal is created between engaging surfacesof the olive and the connector body.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element upon application        of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially circularin cross-section. In exemplary embodiments, the profile of theintermediate portion is concave in cross-section. In exemplaryembodiments, the intermediate portion is tapered towards the contactportion. In exemplary embodiments, the seal element is metallic.

In exemplary embodiments, the apparatus further comprises a mechanismfor applying a force to the first metallic element, in order to assure aseal between a pipe and the connector body.

In exemplary embodiments, the connector body comprises one or moreapertures defining a plurality of channels through a portion of theconnector body, from the front surface of the connector body to a radialinternal surface, the radial internal surface being locatedsubstantially adjacent the first metallic element in use. Force applyingcomponents, such as bolts, can be inserted in the channels within theconnector body to apply a force to the first metallic element, to induceaxial movement of the first metallic element in the direction of thesecond metallic element.

In exemplary embodiments, each channel comprises an internal thread suchthat a bolt, with a corresponding external thread, can be rotatablyinserted into each channel to provide a force that acts on the firstmetallic element in an axial direction.

In exemplary embodiments, the mechanical seal arrangement furthercomprises a resilient washer arranged for sustaining the force appliedon the first metallic element. In exemplary embodiments, the washer isintended to account for any variation in the force (e.g. a reduction inapplied force as the bolts, or another appropriate method of applyingforce, loosen over time) to ensure that a strong seal is maintainedbetween the mechanical seal arrangement and the connector body.

In exemplary embodiments, the washer is configured to be located betweenthe radial internal surface of the connector body comprising theapertures, and the first metallic element. Advantageously, the washerprotects the first metallic element from damage, such as abrasion thatmight otherwise occur if the force applying components contacted thefirst metallic element directly.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection on an internal surface of the connector body. Insuch embodiments, the projection is intended for alignment with acorresponding groove on the external surface of the pipe to be insertedinto the connector. In use, the projection and groove engage oneanother, to substantially prevent or limit axial movement of theconnector body relative to the free ends of the pipes.

In exemplary embodiments, one or both of the projections on theconnector body and the groove on the pipe are circumferential.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one circumferential groove on an internal surface of theconnector body. In such embodiments, the groove is intended foralignment with a corresponding groove on the external surface of thepipe to be inserted into the connector, in order to define a bore orchannel between the connector body and the pipe, for receiving a lockingelement, e.g. a length of wire, in order to resist against separation ofthe pipe and connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, e.g. for locating in a bore or channelformed between the connector body and a pipe received therein.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, such that they can be brought together aroundthe pipes, in use.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

Advantageously, installation of the apparatus is simplified, as thefirst and second parts of the connector body can be brought together ina transverse direction around the remaining components of the apparatus.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to eachother.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

A further aspect of the invention provides a pipe assembly connectingtwo pipes in fluid communication, the assembly comprising two pipes,each having a free end, a connector body bridging the pipes; and amechanical seal arrangement for providing a metal-to-metal seal betweeneach pipe and the connector body.

Similarly to the previous aspect of the invention, in normal use, theassembly serves to connect the two pipes in fluid communication. It willbe understood that a seal is required between each pipe and theconnector body. The metal-on-metal arrangement provides a very strongseal, suitable for withstanding high pressures and high temperatures. Ametal seal also has a high resistance to corrosion, increasing the lifeof the seal, especially when compared to traditional seals, such asrubber or asbestos O-rings or gaskets.

In exemplary embodiments, the mechanical seal arrangement comprises afirst metallic element and a second metallic element, the first andsecond metallic elements arranged to engage each other to create ametal-to-metal seal.

In exemplary embodiments, the first metallic element is an olive havinga tapered portion comprising an angled surface, arranged to contact acorresponding angled surface of the second metallic element. Inexemplary embodiments, the second metallic element is a sleeve,configured to fit within the connector body and encircle the two freeends of the pipes. In exemplary embodiments, the sleeve is configured tobridge the free ends of the pipes in use. In exemplary embodiments, thetwo angled surfaces have slightly different angles.

In alternative embodiments, the sleeve is integral with the connectorbody, such that, in use, the seal is created between engaging surfacesof the olive and the connector body.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element upon application        of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially circularin cross-section. In exemplary embodiments, the profile of theintermediate portion is concave in cross-section. In exemplaryembodiments, the intermediate portion is tapered towards the contactportion. In exemplary embodiments, the seal element is metallic.

In exemplary embodiments, the assembly further comprises a mechanismarranged to act on the first metallic element, applying a force, toinduce axial movement of the first metallic element in the direction ofthe second metallic element.

In exemplary embodiments, the connector body comprises one or moreapertures defining a plurality of channels through a portion of theconnector body, from the front surface of the connector body to a radialinternal surface substantially adjacent the first metallic element.

In exemplary embodiments, the assembly further comprises a resilientwasher, located between the connector body and the first metallicelement, to assure the force applied on the first metallic element inuse.

In exemplary embodiments, a mechanical interlock arrangement isprovided.

The mechanical interlock arrangement helps to prevent undesiredseparation of the pipes. It also greatly simplifies the installationprocess, as relatively little needs to be done on site to install theassembly, compared to existing methods.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection on an internal surface of the connector body. Insuch embodiments, the projection is intended for alignment with acorresponding groove on the external surface of the pipe to be insertedinto the connector. In use, the projection and groove engage oneanother, to substantially prevent or limit axial movement of theconnector body relative to the free ends of the pipes.

In exemplary embodiments, one or both of the projections on theconnector body and the groove on the pipe are circumferential.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one circumferential groove on an internal surface of theconnector body. In such embodiments, the groove is intended foralignment with a corresponding groove on the external surface of thepipe to be inserted into the connector, in order to define a bore orchannel between the connector body and the pipe, for receiving a lockingelement, e.g. a length of wire, in order to resist against separation ofthe pipe and connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, e.g. for locating in a bore or channelformed between the connector body and a pipe received therein.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody.

In exemplary embodiments, the barb is circumferential.

In exemplary embodiments, the barb is tapered.

In exemplary embodiments, the connector body is provided as separatefirst and second parts, the first and second parts having been broughttogether around the pipes.

In exemplary embodiments, the connector body is split along a horizontalplane to define the first and second parts.

In exemplary embodiments, the connector body is provided as separateends or parts, such that a first part is on or around a first pipe freeend and a second part is on or around a second pipe free end. Inexemplary embodiments, the connector body is split along a verticalplane.

In exemplary embodiments, the first and second parts of the connectorbody comprise bores extending in a direction perpendicular to thehorizontal plane, configured to accept connecting components, in orderto couple the first and second parts of the connector body to eachother.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

A further aspect of the invention provides a method of connecting twopipes in fluid communication, the method comprising providing two pipes,each pipe having a free end; locating a first part of a metal-to-metalseal arrangement on the free end of each pipe; and locating each freeend of the pipe within a connector body having a second part of ametal-to-metal seal arrangement, such that the connector body bridgesthe two pipes; wherein the first and second metal-to-metal sealarrangements provide a metal-to-metal seal between a respective pipe andthe connector body.

Advantageously, the method of connecting the two pipes is very simpleand easily repeatable, meaning that minimal training is required toperform the method. Also, in the case of pipe repairs, downtime isgreatly reduced compared to current methods, minimising the cost of anyrepairs. Moreover, the method avoids the need for flanges used commonlyfor coupling two pipes together in fluid communication.

In exemplary embodiments, the method comprises the step of applying aforce to the first part of the seal arrangement, in order to assure aseal between the pipe and the connector body.

In exemplary embodiments, the method also comprises the step ofproviding a mechanical interlock arrangement, for preventing or limitingaxial movement of the connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesforming a groove on an outside surface of at least one pipe andproviding a projection on an internal surface of the connector body, andengaging the projection with the groove to prevent or limit axialmovement of the connector body relative to the pipes.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one circumferential groove on an internal surface of theconnector body. In such embodiments, the groove is intended foralignment with a corresponding groove on the external surface of thepipe to be inserted into the connector, in order to define a bore orchannel between the connector body and the pipe, for receiving a lockingelement, e.g. a length of wire, in order to resist against separation ofthe pipe and connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, e.g. for locating in a bore or channelformed between the connector body and a pipe received therein.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

In exemplary embodiments, the method further comprises providing aresilient washer between the connector body and the first part of theseal arrangement, for applying a force to the seal element.

A further aspect of the invention provides a coupling arrangementcomprising a connector and a pipe, the connector having a female openend configured to receive a male free end of the pipe, the couplingarrangement further comprising a mechanical seal arrangement configuredto form a metal-to-metal seal between the connector and the pipe,wherein the mechanical seal arrangement comprises a first angled surfaceand a second angled surface, the first and second angled surfaces beingarranged to engage each other to form the metal-to-metal seal.

The coupling arrangement has multiple advantages and applications. Forexample, the coupling arrangement can form part of a known expansionjoint without the need for any welding.

In exemplary embodiments, the mechanical seal arrangement includes afirst metallic element configured to fit on the free end of the pipe,the metallic element including the first angled surface.

In exemplary embodiments, the connector comprises the second angledsurface, e.g. part of a metal sleeve or other metallic element housedwithin the connector, or an integral part of the connector body orsocket defining the female open end.

In exemplary embodiments, the first metallic element is an olive havinga tapered portion comprising the first angled surface, arranged tocontact the second angled surface of the connector. In exemplaryembodiments, the first and second angled surfaces have different angles.In use, the first angled surface abuts the second angled surface,forming a strong seal.

In exemplary embodiments, the first metallic element is an annular sealelement for sealing a pipe joint, the seal element comprising:

-   -   a loading surface, an intermediate portion and a contact        portion;    -   the loading surface being configured to receive an axial force        and transmit the force via the intermediate portion to the        contact portion, and the contact portion being configured to        provide a seal between the pipe and a surrounding secondary seal        element;    -   wherein the contact portion is configured to project radially        beyond the intermediate portion and thereby provide a        predetermined annular deformation region configured to conform        to and seal against the secondary seal element upon application        of a predetermined axial force.

In exemplary embodiments, the contact portion is configured to projectradially outward beyond the intermediate portion.

In exemplary embodiments, the contact portion is configured to projectradially inward beyond the intermediate portion.

In exemplary embodiments, the contact portion is substantially circularin cross-section. In exemplary embodiments, the profile of theintermediate portion is concave in cross-section. In exemplaryembodiments, the intermediate portion is tapered towards the contactportion. In exemplary embodiments, the seal element is metallic.

In exemplary embodiments, the apparatus further comprises a mechanismfor applying a force to the metallic element, in order to assure a sealbetween the pipe and the connector.

In exemplary embodiments, the coupling arrangement further comprises acap, configured to encircle the pipe, the cap defining a cavity forhousing the first metallic element.

In exemplary embodiments, the cap comprises one or more aperturesdefining a plurality of channels through a portion of the cap, from afront surface of the cap to a radial internal surface, the radialinternal surface being located substantially adjacent the first metallicelement in use.

Force applying components, such as bolts, can be inserted in thechannels within the cap to apply a force to the first metallic element,to induce axial movement of the metallic element in the direction of thesecond angled surface of the connector.

In exemplary embodiments, each channel comprises an internal thread suchthat a bolt, with a corresponding external thread, can be rotatablyinserted into each channel to provide a force that acts on the metallicelement in an axial direction.

In exemplary embodiments, the mechanical seal arrangement furthercomprises a resilient washer arranged for sustaining the force appliedon the first metallic element, the resilient washer being located withinthe cavity defined by the cap. In exemplary embodiments, the washer isintended to substantially account for any variation in the force (e.g. areduction in applied force as the bolts, or another appropriate methodof applying force, loosen over time) to ensure that a strong seal ismaintained between the pipe and the connector.

In exemplary embodiments, the washer is configured to be located betweenthe radial internal surface of the cap comprising the apertures, and thefirst metallic element. Advantageously, the washer protects the firstmetallic element from damage, such as abrasion that might otherwiseoccur if the force applying components contacted the first metallicelement directly.

In exemplary embodiments, the coupling arrangement further comprises amechanical interlock arrangement, for preventing or limiting axialmovement of the connector relative to the free end of the pipe.

In exemplary embodiments, the mechanical interlock arrangement comprisesa first projection on an internal surface of the cap. In suchembodiments, the first projection is intended for alignment with acorresponding groove on an external surface of the pipe to be insertedinto the connector. In use, the first projection and the groove on thepipe engage one another.

In exemplary embodiments, one or both of the projections and the grooveare circumferential.

In exemplary embodiments the mechanical interlock arrangement furthercomprises a second projection on the internal surface of the cap. Insuch embodiments, the second projection is intended for alignment with acorresponding groove on an external surface of the connector. In use,the second projection and the groove on the connector engage oneanother.

In alternative embodiments, the internal surface of the cap has a threadand the external surface of the connector has a corresponding thread,such that the cap can be screwed on to the connector to prevent or limitaxial movement of the connector relative to the free end of the pipe.

In exemplary embodiments, the cap comprises separate first and secondparts, such that, after assembly, they encircle the pipe.

In exemplary embodiments, the cap is split along a horizontal plane todefine the first and second parts.

Advantageously, installation of the coupling arrangement is simplified,as the first and second parts of the cap can be brought together in atransverse direction around the remaining components of the couplingarrangement.

In exemplary embodiments, the first and second parts of the cap comprisebores extending in a direction perpendicular to the horizontal plane,configured to accept connecting components, in order to couple the firstand second parts of the cap to each other.

In exemplary embodiments, each bore comprises an annular surface with aplane parallel to the horizontal plane, configured to be engaged by aconnecting component in use.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one circumferential groove on an internal surface of theconnector body. In such embodiments, the groove is intended foralignment with a corresponding groove on the external surface of thepipe to be inserted into the connector, in order to define a bore orchannel between the connector body and the pipe, for receiving a lockingelement, e.g. a length of wire, in order to resist against separation ofthe pipe and connector body.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one length of wire, e.g. for locating in a bore or channelformed between the connector body and a pipe received therein.

In exemplary embodiments, the mechanical interlock arrangement comprisesat least one projection or barb on an internal surface of the connectorbody. In exemplary embodiments, the barb is circumferential. Inexemplary embodiments, the barb is tapered.

Other aspects and features of the invention will be apparent from theclaims and the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to theaccompanying drawings, in which:

FIG. 1 is a perspective view of a pipe assembly according to an aspectof the invention;

FIG. 2 is a cut-away perspective view of the pipe assembly of FIG. 1,showing the components that make up the pipe assembly;

FIG. 3 is a cross-sectional view of the pipe assembly of FIG. 1;

FIG. 4 is a perspective view of a connector body, a component of thepipe assembly of FIG. 1;

FIG. 5 is a perspective view of an olive, a component of the pipeassembly of FIG. 1;

FIG. 6 is a perspective view of a nut, a component of the pipe assemblyof FIG. 1;

FIG. 7 is a perspective view of a resilient washer, a component of thepipe assembly of FIG. 1;

FIG. 8 is a perspective view of a pipe assembly according to an aspectof the invention;

FIG. 9 is a cut-away perspective view of the pipe assembly of FIG. 8,showing the components that make up the pipe assembly;

FIG. 10 is a cross-sectional view of the pipe assembly of FIG. 8;

FIG. 11 is a perspective view of a connector body, a component of thepipe assembly of FIG. 8;

FIGS. 12A and 12B are perspective views of a nut, a component of thepipe assembly of FIG. 8;

FIG. 13 is a perspective view of a pipe assembly according to an aspectof the invention;

FIG. 14 is a cut-away perspective view of the pipe assembly of FIG. 13through a horizontal plane, showing the components that make up the pipeassembly;

FIG. 15 is a close-up view of the pipe assembly of FIG. 13;

FIG. 16A is a perspective view of a pipe, a component of the pipeassembly of FIG. 13;

FIG. 16B is a cross-sectional view of the pipe of FIG. 16A;

FIG. 17A is a perspective view of a connector body, a component of thepipe assembly of FIG. 13;

FIG. 17B is a cross-sectional view of the connector body of FIG. 17A;

FIG. 17C is a front view of the connector body of FIG. 17A;

FIG. 17D is a plan view of the connector body of FIG. 17A;

FIG. 18A is a sleeve, a component of the pipe assembly of FIG. 13;

FIG. 18B is a cross-sectional view of the sleeve of FIG. 18A;

FIG. 19A is a perspective view of an olive, a component of the pipeassembly of FIG. 13;

FIG. 19B is a cross-sectional view of the olive of FIG. 19A;

FIG. 20A is a perspective view of a resilient washer, a component of thepipe assembly of FIG. 13;

FIG. 20B is a cross-sectional view of the resilient washer of FIG. 20A;

FIG. 20C is a close up cross-sectional view of the resilient washer ofFIG. 20A;

FIG. 21 is a perspective view of a further aspect of the invention,showing a coupling arrangement, located between a pipe and a connector;

FIG. 22 is a cross-sectional view of the coupling arrangement of FIG.21; and.

FIG. 23 is a plan view of the coupling arrangement of FIG. 21;

FIG. 24 is a perspective view of a pipe assembly according to an aspectof the invention;

FIG. 25 is a cross-sectional view of the pipe assembly of FIG. 24;

FIG. 26A is a perspective view of a seal element or olive, a componentof the pipe assembly of FIG. 24;

FIG. 26B is a side view of the seal element or olive of FIG. 26A;

FIG. 27 is a perspective view of a connector body, a component of thepipe assembly of FIG. 24; and

FIG. 28 is a perspective view of a sleeve, a component of the pipeassembly of FIG. 24.

DETAILED DESCRIPTION OF THE INVENTION

Referring firstly to FIGS. 1 to 3, an assembly connecting two pipes influid communication is indicated generally at 100. The assembly includestwo pipes 102, bridged by a connector body 104. The connector body 104has opposing open ends, configured to accept a free end of a pipe 102.

As will be described in more detail below, axial movement of the pipes102 relative to the connector body 104 is prevented or limited by amechanical interlock arrangement 106. In this embodiment, the mechanicallock arrangement 106 includes a plurality of lengths of wire 160,engaging in grooves formed in the pipes 102 and connector body 104. Amechanical seal arrangement 108 provides a seal between the pipes andthe connector body. The mechanical seal arrangement 108 includes ametallic element such as, in this embodiment, a metal olive 130. Themechanical seal arrangement 108 further includes a cap 109, such as anut 140. In this embodiment, the nut 140 is located at each opposing endof the connector body 104 and is used to provide a compressive force onthe olive 130, creating a seal between the olive 130 and the connectorbody 104.

In this embodiment, each pipe 102 is approximately 100 mm in diameter(i.e. a relatively large diameter pipe suitable for transporting oil, orthe like, at high pressure). Each pipe 102 has two grooves 103, locatedgenerally adjacent the free end of the pipe 102. Each groove 103 extendsaround an entire external circumference of the pipe 102. The grooves 103are generally semi-circular in cross-section and can be formed by anysuitable method, such as machining. It will be appreciated, however,that each groove 103 may be of any suitable shape in cross-section andmay only extend for a partial external circumference of the pipe.

Referring to FIG. 4, the connector body 104 defines a sleeve 110 in theform of a generally hollow cylinder having opposing open ends,approximately 200 mm in length with a bore of between 100.08 and 100.11mm in this embodiment, such that it can receive the free ends of the twopipes 102 with a small clearance. The sleeve 110 has an internalshoulder 112 projecting from an internal surface 114. The internalshoulder 112 acts as a stop for the free ends of the pipes 102, in use.The internal shoulder 112 extends around an entire internalcircumference of the sleeve 110, though it will be appreciated that theinternal shoulder 112 may only extend around one or more portions of theinternal circumference of the sleeve 110. In this embodiment, theinternal shoulder 112 is located in the centre of the sleeve 110longitudinally, such that an equal amount of the each pipe 102 isreceived in each open end of the sleeve 110. This position has beenfound to give a desirable force distribution when the sleeve 110 is inuse, though it will be appreciated that the internal shoulder 112 can belocated in any suitable position within the sleeve 110, or may beremoved completely, e.g. in some instances of the sleeve being used torepair two broken pipes.

The internal surface 114 of the sleeve 110 also has a plurality ofgrooves 116. In this embodiment, there are four grooves 116, with twogrooves 116 located on either side of the internal shoulder 112longitudinally. Each groove 116 extends around the entire internalcircumference of the sleeve 110 and is generally semi-circular incross-section. Each groove 116 connects to an aperture 118. There aretherefore four apertures 118 in total, distributed in horizontalalignment along one side of the sleeve 110. Each aperture 118 passesfrom an external surface 115 of the sleeve to the internal surface 114,creating a plurality of passages from the external surface 115 to thegrooves 116.

The sleeve 110 has opposing end surfaces 120. As can be seen mostclearly from FIG. 3, the end surfaces 120 of the sleeve 110 are made upof a first surface portion 120 a and a second surface portion 120 b. Thesurface portion 120 a is radial, i.e. it projects in a substantiallyperpendicular direction to the longitudinal axis of the sleeve 110, andis substantially flat in this embodiment. Connecting the surface portion120 a to the internal surface 114 is the surface portion 120 b. Thesurface portion 120 b is angled, having an angle of approximately 12° tothe longitudinal axis of the sleeve 110 and 24° inclusive in thisembodiment. The angled surface portion 120 b is substantially flat inthis embodiment.

Substantially adjacent the end surfaces 120 at each end of the sleeve110, on the external surface 115, is a groove 122. The groove 122extends around the entire external circumference of the sleeve 110 andis generally semi-circular in cross-section. Laterally inward of thegroove 122 is a shoulder 124. In this embodiment, the shoulder 124extends around an entire external circumference of the sleeve 110, butit will be appreciated that the shoulder 124 may only extend for one ormore portions of the external circumference of the sleeve 110.

Referring to FIGS. 3 and 5, the olive 130 is composed of two annularportions 130 a and 130 b. The annular portion 130 a is generallyrectangular in cross section, i.e. an internal surface 132 and anexternal surface 133 of the annular portion 130 a are parallel. Theannular portion 130 a has a front surface 134 that connects the internalsurface 132 and the external surface 133. Projecting in a generallyperpendicular direction from the front surface 134 is the annularportion 130 b. The annular portion 130 b is generally tapered. Theannular portion 130 b has a smaller external diameter than the annularportion 130 a. The annular portion 130 b has an internal surface 136that is coplanar to the internal surface 132, such that the two surfacesform a continuous planar surface, creating a constant bore through theolive 130. The annular portion 130 b also has an external surface 138.The external surface 138 is angled, at approximately 10° to the plane ofthe internal surface 136 and 20° inclusive, to create the taper of theannular portion 130 b. The external surface 138 is generally flat.Connecting the external surface 138 to the external surface 133 is arear surface 135 of the olive 130.

Referring to FIGS. 3 and 6, the nut 140 is generally hat-shaped incross-section. The nut 140 generally comprises an annular portion 142,an annular portion 146, and a bridging portion 144 connecting theannular portion 142 to the annular portion 146. The bore of the annularportion 142 is between 100.08 and 100.11 mm in this embodiment (i.e.sufficient to fit a 100 mm pipe, with a small clearance). The bore ofthe bridging portion 144 and the annular portion 146 are greater thanthe bore of the annular portion 142, and are approximately equal to theexternal diameter of the sleeve 110 and the external diameter of theannular portion 130 a of the olive 130; in this embodiment about 150 mm.For the purposes of this description, it will be assumed that theannular portion 142 is the front of the nut 140 and the annular portion146 is the rear of the nut 140.

The annular portion 142 has an internal surface 142 a, an externalsurface 142 c and a front surface 142 b, that connects the internalsurface 142 a and the external surface 142 c. The internal surface 142 aand the external surface 142 c are parallel, and the front surface 142 bis perpendicular to both surfaces. Distributed evenly around the frontsurface 142 b, on an appropriate pitch circle, are a plurality ofapertures 143. In this embodiment, there are twelve circular apertures143, but any suitable shape and number of apertures 143 may be included.The apertures 143 pass through the entire depth of the annular portion142, i.e. from the front surface 142 b to a rear surface 142 d.

The bridging portion 144 connects the annular portion 142 to the annularportion 146. The bridging portion 144 has an internal surface 144 a andan external surface 144 c. The external surface 144 c is coplanar to theexternal surface 142 c, such that the two surfaces form a continuousplanar surface. The internal surface 144 a is parallel to the externalsurface 144 c.

Connected to the bridging portion 144 is the annular portion 146. Theannular portion 146 has an internal surface 146 a, a rear surface 146 d,an external surface 146 c, and a front surface 146 b. The internalsurface 146 a is coplanar to the internal surface 144 a, such that thetwo surfaces form a continuous planar surface. The external surface 146c is parallel to the internal surface 146 a. The rear surface 146 dconnects the external surface 146 c to the internal surface 146 a. Therear surface 146 d is perpendicular to the external surface 146 c andthe internal surface 146 a. The front surface 146 b is parallel to therear surface 146 d, and connects the external surface 146 c to theexternal surface 144 c.

On the internal surface 146 a of the annular portion 146 is a groove148. In this embodiment, the groove 148 extends around the entireinternal circumference of the annular portion 146 of the nut 140 and isgenerally semi-circular in cross-section. On the external surface 146 cis an aperture 149. The aperture 149 is located longitudinally levelwith the groove 148, creating a passage from the external surface 146 cto the groove 148.

In this embodiment, the assembly 100 further includes a resilient washer150. Referring now to FIG. 7, the washer 150 is a spring washer. Thewasher 150 is annular, with a semi-circular cross section. In thisembodiment, the washer comprises a shoulder 154 protruding in adirection perpendicular to a top surface 152 of the washer 154. Theshoulder 154 is also annular, with an internal diameter equal to theinternal diameter of the remainder of the washer 150, such that thewasher 150 has a constant bore through its centre. The washer 150 istypically made of metal, such as steel. Preferably a sprung steel willbe used, with a high yield strength and high elastic modulus, such asmedium/high carbon-steel, but any suitable material can be used. It willalso be appreciated that any suitable type of resilient washer may beused.

To assemble the components of the assembly 100, firstly the grooves 103are formed in the appropriate places on the free ends of the pipes 102.Then, taking each pipe 102 individually, the nut 140 is slid onto thepipe 102. Next, the washer 150 is slid on to the pipe 102. The washer150 is dimensioned to have an internal diameter similar to the pipe 102and an external diameter similar to the bore of the bridging portion 144of the nut 140. Therefore, the washer 150 fits in the bore of thebridging portion 144 and contacts the rear surface 142 d of the annularportion 142. The olive 130 is then slid on to the pipe 102, such thatthe front surface 134 of the annular portion 130 a contacts the washer150, and the olive 130 is housed within the bore of the bridging portion144. The washer 150 is arranged such that the shoulder 154 of the washer150 abuts the front surface 134 of the olive 130 in use. This enablesthe washer to deflect about its shoulder to sustain the force andsubstantially limit the movement of the olive 130.

The sleeve 110 is slid on to the pipe 102 next, until the free end ofthe pipe 102 comes into contact with the shoulder 112. The shoulder 112is dimensioned to project outwardly from the internal surface 114 of thesleeve to a distance such that a top surface 112 a of the shoulder issubstantially level with the internal diameter of the pipe 102. Thisminimises turbulence in the pipe 102 when it is in use, advantageouslyimproving the efficiency of the fluid flow within the pipe 102. When thepipe 102 is in contact with the shoulder 112, the grooves 103 of thepipe 102 line up with the grooves 116 of the sleeve 110, formingchannels with a circular cross section between the sleeve 110 and thepipe 102.

The nut 140 is then slid back over the sleeve 110, in the direction ofthe end of the pipe 102, until the rear surface 146 d contacts theshoulder 124 in the external surface 115 of the sleeve 110. When the nut140 is in contact with the shoulder 124, the groove 122 of the sleeve110 lines up with the groove 148, creating a channel between the sleeve110 and the nut 140.

The same process is repeated on the other pipe 102 of the joint suchthat the assembly bridges the gap between two pipes 102.

A separate length of wire 160 is threaded through each of the apertures118 and the apertures 149, and through the passages created between thecorresponding components. The wire 160 provides sufficient strength toprevent or limit the relative movement of the components of the assemblyaxially, i.e. along the longitudinal axis of the sleeve 110. Each lengthof wire 160 is dimensioned to fit within at least one of the passagesand have an appropriate length. In this embodiment, it is held in placeby square plugs. This is advantageous as a user simply needs an Allenkey for installation of the assembly 110. It will be appreciated though,that any suitable method could be used to hold the wire in place.

A plurality of bolts 152 are then inserted through the apertures 143from the front surface 142 b in the direction of the rear surface 142 dof each nut 140. They pass through and contact the washer 150. As thebolts 152 are tightened, a force is therefore applied to the washer 150and is transferred to the olive 130. The washer 150 advantageouslyensures that the force applied by the nut 140 is maintained in use, asit can account for any natural ‘flex’ that may occur between the nut 140and the olive 130, as well as any decrease in the force applied by blots152 over time, or if they loosen in use. It also protects the olive 130from abrasive damage from the bolts 152.

The force applied by the bolts 152 compresses the olive 130 in thedirection of the sleeve 110. Specifically, the angled surface 138 of theolive 130 engages the angled surface 120 b of the sleeve 110. The angledsurfaces interface and the olive 130 conforms to the greater angle ofthe surface 120 b of the sleeve 110. This creates a strong mechanicalseal between the sleeve 110 and the olive 130.

Therefore, in use, oil can pass from one pipe 102 to another pipe 102under high pressure with a very low risk of leakage due to the strongmechanical seal created by the assembly 100.

Referring now to FIGS. 8 to 10, a second embodiment of the inventionwill be described. This embodiment works in a very similar way to thefirst embodiment but has a modified mechanical interlock arrangement.Equivalent parts of each embodiment use equivalent labels; 102, 202 etc.

A pipe assembly is indicated generally at 200. The assembly includes twopipes 202, bridged by a connector body 204. The connector body 204 hasopposing open ends, configured to accept a free end of a pipe 202.

As will be described in more detail below, axial movement of the pipes202 relative to the connector body 204 is prevented or limited by amechanical interlock arrangement 206. In this embodiment, the mechanicalinterlock arrangement 206 includes a plurality of lengths of wire 260,engaging in grooves formed in the pipes 202 and grooves formed within amechanical seal arrangement 208 (described below). The mechanicalinterlock arrangement also includes a threaded connection between theconnector body 204 and the mechanical seal arrangement 208. Themechanical seal arrangement 208 provides a seal between the pipes andthe connector body. The mechanical seal arrangement 208 includes ametallic element such as, in this embodiment, a metal olive 230. Themechanical seal arrangement 208 further includes a cap 209, such as anut 240. In this embodiment, the nut 240 is located at each opposing endof the connector body 204 and is used to provide a compressive force onthe olive 230, creating a seal between the pipes and the connector body204.

In this embodiment, each pipe 202 is approximately 100 mm in diameter(i.e. a relatively large diameter pipe suitable for transporting oil, orthe like, at high pressure). Each pipe 202 has at least one groove 203,spaced from the free end of the pipe 202. Each groove 203 extends aroundan entire external circumference of the pipe 202. The grooves 203 aregenerally semi-circular in cross-section and can be formed by anysuitable method, such as machining. It will be appreciated, however,that each groove 203 may be of any suitable shape in cross-section andmay only extend for a partial external circumference of the pipe.

Referring to FIG. 11, the connector body 204 defines a sleeve 210 in theform of a generally hollow cylinder having opposing open ends,approximately 200 mm in length, and with a bore of between 100.08 and100.11 mm in this embodiment, such that it can receive the free ends ofthe two pipes 202 with a small clearance. The sleeve 210 has an internalsurface 214, which is generally planar.

The sleeve 210 has opposing end surfaces 220. As can be seen mostclearly from FIG. 11, the end surfaces 220 of the sleeve 210 are made upof a first surface portion 220 a and a second surface portion 220 b. Thesurface portion 220 a is radial, i.e. it projects in a substantiallyperpendicular direction to the longitudinal axis of the sleeve 210, andis substantially flat in this embodiment. Connecting the surface portion220 a to the internal surface 214 is the surface portion 220 b. Thesurface portion 220 b is angled, having an angle of approximately 12° tothe longitudinal axis of the sleeve 210 and 24° inclusive in thisembodiment. The angled surface portion 220 b is substantially flat inthis embodiment.

Substantially adjacent the end surfaces 220 at each end of the sleeve210, between the end surface 220 and the external surface 215, is athreaded portion 217. The threaded portion 217 extends around the entireexternal circumference of the sleeve 210. The outer diameter of thesleeve 210 is lower for the extent of the threaded portion 217 than theouter diameter of the remainder of the sleeve 210, such that the nut 240can be received on the end of the sleeve 210. Further, the lower outerdiameter of the threaded portion 217 creates a surface 219,perpendicular to the external surface 215 of the sleeve 110 (or thelongitudinal axis of the sleeve 110).

The olive 230 is composed in substantially the same way as the olive 130of the first embodiment and will not be described again.

Referring to FIGS. 10, 12 a and 12 b, the nut 240 is generally u-shapedin cross-section. The nut 240 generally defines an annular portion 242,and an annular portion 244. The bore of the annular portion 242 isbetween 100.08 and 100.11 mm in this embodiment (i.e. sufficient to fita 100 mm pipe, with a small clearance). The bore of the annular portion244 is greater than the bore of the annular portion 242, and isapproximately equal to the external diameter of the sleeve 210 and theexternal diameter of the annular portion 230 a of the olive 230; in thisembodiment about 150 mm. For the purposes of this description, it willbe assumed that the annular portion 242 is the front of the nut 240 andthe annular portion 244 is the rear of the nut 240.

The annular portion 242 has an internal surface 242 a, an externalsurface 242 c and a front surface 242 b, that connects the internalsurface 242 a and the external surface 242 c. The internal surface 242 aand the external surface 242 c are parallel, and the front surface 242 bis perpendicular to both surfaces. Distributed evenly around the frontsurface 242 b, on an appropriate pitch circle, are a plurality ofapertures 243. In this embodiment, there are twelve circular apertures243, but any suitable shape and number of apertures 243 may be included.The apertures 243 pass through the entire depth of the annular portion242, i.e. from the front surface 242 b to a rear surface 242 d.

Connected to the annular portion 242 is the annular portion 244. Theannular portion 244 has an internal surface 244 a and an externalsurface 244 c. The external surface 244 c is coplanar to the externalsurface 242 c, such that the two surfaces form a continuous planarsurface. The internal surface 244 a is parallel to the external surface244 c. The internal surface also has a rear surface 244 d connecting theinternal surface 244 a to the external surface 244 c, the rear surface244 d being perpendicular to both the internal surface 244 a and theexternal surface 244 c.

On the internal surface 244 a of the annular portion 244, generallyadjacent the rear surface 244 d, is a threaded portion 245. In thisembodiment, the threaded portion 245 extends around the entire internalcircumference of the annular portion 244 of the nut 240 and correspondsto the threaded portion 217 of the sleeve 210 such that, in use, the nut240 engages the sleeve 210 to create a secure threaded connection. Thisadvantageously creates a large amount of rigidity in the assembly 200.

The internal surface 242 a includes two grooves 247, located generallyadjacent the front surface 242 b of the annular portion 242. Each groove247 extends around an entire internal circumference of the annularportion 242. The grooves 247 are generally semi-circular incross-section and can be formed by any suitable method, such asmachining. It will be appreciated, however, that each groove 247 may beof any suitable shape in cross-section, may only extend for a partialinternal circumference of the annular portion 242 of the nut 240, andthere may be either more or less grooves included. The external surface242 c includes at least one aperture 249. The aperture 249 is locatedlongitudinally level with at least one groove 247, creating a passagefrom the external surface 244 c to the grooves 247.

In this embodiment, the assembly 200 further includes a resilient washer250, which is composed in substantially the same way as the resilientwasher 150 of the first embodiment and will not be described again.

To assemble the components of the assembly 200, taking each pipe 202individually, the two grooves 203 are machined into the pipe, thegrooves being spaced from the free end such that, in use, they line upwith the grooves 247 on the nut 240. Then, the nut 240 is slid onto thepipe 202. Next, the washer 250 is slid on to the pipe 202. The washer250 is dimensioned to have an internal diameter similar to the pipe 202and an external diameter similar to the bore of the annular portion 244of the nut 240. Therefore, the washer 250 fits in the bore of theannular portion 244 and contacts the rear surface 242 d of the annularportion 242. The olive 230 is then slid on to the pipe 202, such thatthe front surface 234 of the annular portion 230 a contacts the washer250, and the olive 230 is housed within the bore of the annular portion244. The washer 250 is arranged such that the shoulder 254 of the washer250 abuts the front surface 234 of the olive 230 in use. This enablesthe washer to deflect about its shoulder to sustain the force andsubstantially limit the movement of the olive 230.

The sleeve 210 is slid on to the pipe 202 next. The nut 240 is thenscrewed back over the sleeve 210, in the direction of the end of thepipe 202, until the rear surface 244 d abuts the surface 219 of thesleeve 210, and the threaded portions 217 and 245 are engaged. When thenut 240 is in contact with the surface 219 of the sleeve 210, thegrooves 247 of the nut 240 line up with the grooves 203 of the pipe 202,creating a channel between the nut 240 and the pipe 202.

The same process is repeated on the other pipe 202 of the joint suchthat the assembly bridges the gap between two pipes 202.

A separate length of wire 260 is threaded through each of the apertures249, and through the passages created between the correspondingcomponents. The wire 260 provides sufficient strength to prevent orlimit the relative movement of the components of the assembly axially,i.e. along the longitudinal axis of the sleeve 210. Each length of wire260 is dimensioned to fit within at least one of the passages and havean appropriate length. In this embodiment, it is held in place by squareplugs. This is advantageous as a user simply needs an Allen key forinstallation of the assembly 210. It will be appreciated though, thatany suitable method could be used to hold the wire in place. The wirereferred to in all embodiments of the invention is generally wire rope,but is not limited to wire rope and could alternatively be solid wire.As the wires 260 are loaded during the installation of the mechanicalseal arrangement and connector body, any movement of the pipes isisolated from the remainder of the components.

A plurality of bolts 252 are then inserted through the apertures 243from the front surface 242 b in the direction of the rear surface 242 dof each nut 240. They pass through and contact the washer 250. As thebolts 252 are tightened, a force is therefore applied to the washer 250and is transferred to the olive 230. The washer 250 advantageouslyensures that the force applied by the nut 240 is maintained in use, asit can account for any natural ‘flex’ that may occur between the nut 240and the olive 230, as well as any decrease in the force applied by thebolts 252 over time, or if they loosen in use. It also protects theolive 130 from abrasive damage from the bolts 252.

The force applied by the bolts 252 compresses the olive 230 in thedirection of the sleeve 210. Specifically, the angled surface 238 of theolive 230 engages the angled surface 220 b of the sleeve 210. The angledsurfaces interface and the olive 230 conforms to the greater angle ofthe surface 220 b of the sleeve 210. This creates a strong mechanicalseal between the sleeve 210 and the olive 230. The tapered designencourages the performance of the seal to increase as the pressurewithin the pipe increases.

Therefore, in use, oil can pass from one pipe 202 to another pipe 202under high pressure with a very low risk of leakage due to the strongmechanical seal created by the assembly 200.

Referring now to FIGS. 13 to 15, a connector assembly connecting twopipes in fluid communication is indicated generally at 300.

The assembly is suitable for a range of fluids, both liquid and gas, forexample oil, foodstuffs and other applications that the skilled personwould appreciate. The assembly includes two pipes 302, bridged by asplit housing, which is a connector body 310 in this embodiment. Theconnector body 310 is configured to accept the two pipes 302.

As will be described in more detail below, axial movement of the pipes302 relative to the connector body 310 is prevented or limited by amechanical interlock arrangement 304. A mechanical seal arrangement 306provides a seal between the pipes 302 and the connector body 310. Themechanical seal arrangement 306 includes metallic elements such as, inthis embodiment, a sleeve 330 and metal olive 340. In this embodiment, acompressive force is provided on the olive 330, in use, creating a sealbetween the olive 340 and the sleeve 330.

In this embodiment, each pipe 302 is approximately 300 mm in diameter(i.e. a relatively large diameter pipe suitable for transporting oil, orthe like, at high pressure). As shown in FIGS. 16A and 16B, each pipe302 has a machined portion 308. In this embodiment, the machined portion308 extends approximately 90 mm in a longitudinal direction from thefree end of each pipe. It is generally of a lower external diameter thanthe remainder of the pipe, e.g. in this embodiment the external diameterof the machine portion is 113 mm, compared to the stock external pipediameter of 114.8 mm. A groove 309 is provided in each pipe 302. Eachgroove 309 extends around an entire external circumference of the pipe302. The grooves 309 are generally rectangular in cross-section and canbe formed by any suitable method, such as machining. In this embodiment,the groove 309 is 10.5 mm wide in cross-section, with a 2 mm radius oneach corner. The radius enables a corresponding projection to be easilyinserted into the groove (described in more detail below). It will beappreciated, however, that each groove 309 may be of any suitable shapein cross-section and may only extend for a partial externalcircumference of the pipe. The external edge of the free end of eachpipe 302 is also chamfered, with a 0.5 mm chamfer in this embodiment.The chamfer helps to break up the edge of the pipe, and can help preventbuild up on the edge of the pipes, e.g. in the pipes are being used inapplications that are required to be sanitary. The smaller gap can alsohelp to prevent corrosion.

Referring now to FIGS. 17A to 17D, the connector body 310 is in the formof a generally hollow cylinder having opposing open ends. In thisembodiment, the pipe connector is approximately 175 mm in length.Although generally a hollow cylinder, the connector body 310 ismanufactured in two parts. The connector body 310 is split in two alonga horizontal plane A-A extending in the direction of the longitudinalaxis of the connector body 310, as illustrated in FIG. 17C. In practice,this means the two halves of the connector body 310 can be broughttogether in order to surround two pipes 302. The internal surface of theconnector body 310 includes a plurality of projections and recesses thathelp form the mechanical interlock arrangement 304, as well asaccommodate the mechanical seal arrangement 306 (described in moredetail below).

The connector body 310 is symmetrical across a transverse central axis.Therefore, the connector body 310 will be described starting from onelongitudinally outer end, the left end as shown in FIG. 17B.

An outer portion 312 of the connector body 310 includes a front surface312 a, substantially perpendicular to the longitudinal axis of theconnector body 310 in this embodiment, and an external surface 312 b,parallel to the longitudinal axis of the connector body 310, andsubstantially extending between the two opposing front surfaces 312 a.More specifically, each surface 312 a is connected to the surface 312 bby a radiused corner, a 2 mm radius in this embodiment. The outerportion 312 also has an internal surface 312 c, which is concentric withthe external surface 312 b. The connector body 310 can house the twopipes 302 with, at most, a very small clearance. In this embodiment, theexternal surface 312 b has a bore of between 113 mm and 113.3 mm.

Adjacent the outer portion 312 is an inwardly projecting portion 314.The projecting portion 314 has an internal surface 314 c parallel withthe longitudinal axis of the connector body, defining a 109.2 mm borethrough this section of the connector body, in this embodiment. Theinternal surface 314 c is connected to the internal surface 312 c by aradiused corner, with a 2 mm radius in this embodiment. The projectingportion 314 is dimensioned to correspond to the groove 309 provided ineach pipe 302, such that the projecting portion 314 fits in the groove309.

Adjacent the projecting portion 314 is a channel 316. The channel 316 isgenerally rectangular, in this embodiment, and is intended toaccommodate components that contribute to the mechanical sealarrangement 306 (described in more detail below). The channel 316 has afront surface 316 a, that is parallel to the front surface 312 a, and isconnected to the internal surface 314 c by a radiused corner, with a 2mm radius in this embodiment. The front surface 316 a extends outwardlyto meet an internal surface 316 c, which is concentric with the externalsurface 312 b. Adjacent the internal surface 316 c is a rear surface 316d, which is parallel with the front surface 316 a but extends inwardlyto a lesser degree than the surface 316 a. Connecting the front surface316 a and the internal surface 316 c is a radiused corner, with a radiusof 1 mm in this embodiment. Similarly, the internal surface 316 c isconnected to the rear surface 316 d with a radiused corner, also with aradius of 1 mm in this embodiment.

The rear surface 316 d defines a front surface of a shoulder 318. Theinternal surface 318 c is concentric with the external surface 312 b,and defines a bore in this section of 120.5 mm in this embodiment. Arear surface 318 d of the shoulder 318 is parallel with the rear surface316 d, but extends downwardly from the internal surface 318 c to alesser amount than the rear surface 316 d extends downwardly from theinternal surface 318 c.

Between the two rear surfaces 318 d therefore, a recess 320 is defined.An internal surface 320 c connects the two rear surfaces 318 d to eachother, and forms a section with a bore of about 129 mm in thisembodiment. The recess 320 is dimensioned such that it can seat thesleeve 330 (described in more detail below).

As shown most clearly in FIG. 17C, the connector body 310 is dividedinto two halves 310 a, 310 b that can be brought together, and coupled,to surround the pipes 302. As shown in FIG. 17D, each half 310 a, 310 bof the connector body 310 includes a plurality of apertures 322. Whenthe two halves 310 a, 310 b of the connector body 310 are broughttogether, each aperture 322 on the first half 310 a lines up with acorresponding aperture 322 on the second half 310 b. This arrangement ofthe apertures defines a plurality of bores 322 a that extend in adirection perpendicular to the plane A-A (shown in FIG. 17C), and alsoin a direction perpendicular to the flat internal surfaces 323 of eachconnector body half (shown in FIG. 14).

The bores 322 a extend from the external surface 312 b of the first halfof the connector body 310 a to the external surface 312 b of the secondhalf of the connector body 310 b. If a bolt, for example, is placedthrough the bore 322 a, it can be seen that the first and second halves310 a, 310 b would be substantially secured from relative movement in atransverse and longitudinal direction.

In this embodiment, when the connector body 310 is viewed in plan as inFIG. 17D, the apertures 322 are distributed longitudinally along theouter peripheries of the connector body halves 310 a, 310 b. In thisembodiment, there are eight apertures 322 on the first half 310 a (fouron each side), corresponding to eight apertures 322 on the second half310 b, such that a plurality of bores 322 a are defined through theconnector body, as described above.

As can also be seen in FIG. 17C, the apertures 322 are configureddifferently on the first half of the connector body 310 a than thesecond half of the connector body 310 b. A planar annular surface 324 isprovided that surrounds an opening of the bore 322 a. It will beappreciated that the annular surface 324 may be provided on the first orsecond halves 310 a, 310 b of the connector body 310. The plane of theannular surface 324 is perpendicular to the direction of the bore 322 aof the aperture 322. It provides a surface to be engaged by a connectingmember, e.g. the head of a bolt, when the first and second halves of theconnector body 310 a, 310 b are coupled. When viewed in plan, theannular surface 324 is shaped like a cut-off circle, with a circularportion 324 a and a flat edge 324 b. The flat edge 324 b is parallelwith the longitudinal axis of the connector body 310 and is adjacent atraverse edge of the connector body 310, when viewed in plan, as in FIG.17C.

A substantially tear shaped groove 326 is defined around the annularsurface 324. The groove 326 follows the profile of the external surface312 b of the connector body 310, i.e. it curves around the connectorbody circumferentially. The outline of the groove 326 is a cut-offellipse, with an elliptical portion 326 a extending from the flat edge324 b of the annular surface 324. The elliptical portion 326 a of thegroove 326 (shown in FIG. 13) connects to the circular portion 324 a ofthe annular surface 324 by a generally concave internal surface 327.Therefore, it can be seen that a void is defined between the annularsurface 324 and the external surface 312 b of the connector body 310.This enables a connecting member, such as a bolt, to be easily insertedby a user during installation. It also enables a bolt head, for example,to sit flush with the annular surface 324 in use, securing the first andsecond halves of the connector body 310 a, 310 b together strongly.

Distributed evenly on the front surface 312 a, on an appropriate pitchcircle, are a plurality of circular apertures 328. The openings of theapertures 328 are flush with the front surface 312 a. The apertures 328extend longitudinally through the outer portion 312 and the projection314 to the front surface of the channel 316, creating a plurality ofchannels 329 through the depth of the outer portion 312 and projection314 of the connector body 310. In this embodiment, there are tenapertures 328 on each front surface 312 a, but it will be appreciatedthat any appropriate number of apertures may be provided, for exampleeight, or twelve.

Seated within the recess 320 of the connector body 310 is the sleeve330. As shown in FIGS. 18A and 18B, the sleeve 330 is generally a hollowcylinder with opposing end surfaces 332. The sleeve 330 has an internalsurface 334 and an external surface 336. The external surface 336 isdimensioned such that the sleeve 330 can fit within the recess 320 witha small clearance, e.g. in this embodiment the longitudinal length ofthe external surface 336 is 76.8 mm. As can be seen most clearly fromFIG. 18B, the end surfaces 332 of the sleeve 330 are made up of a firstsurface portion 332 a and a second surface portion 332 b. The surfaceportion 332 a is radial, i.e. it projects in a substantiallyperpendicular direction to the longitudinal axis of the sleeve 330, andis substantially flat in this embodiment. Connecting the surface portion332 a to the internal surface 334 is the surface portion 332 b. Thesurface portion 332 b is angled, having an angle of approximately 12° tothe longitudinal axis of the sleeve 330 and 24° inclusive in thisembodiment. The angled surface portion 332 b is substantially flat inthis embodiment.

Referring to FIGS. 18A and 18B, the olive 340 is composed of two annularportions 340 a and 340 b. The annular portion 340 a is generallyrectangular in cross section, i.e. an internal surface 342 and anexternal surface 343 of the annular portion 340 a are parallel. Theannular portion 340 a has a front surface 344 that connects the internalsurface 342 and the external surface 343. Projecting in a generallyperpendicular direction from the front surface 344 is the annularportion 340 b. The annular portion 340 b is generally tapered. Theannular portion 340 b has a smaller external diameter than the annularportion 340 a. The annular portion 340 b has an internal surface 346that is coplanar to the internal surface 342, such that the two surfacesform a continuous planar surface, creating a constant bore through theolive 340. The annular portion 340 b also has an external surface 347.The external surface 347 is angled, at approximately 10° to the plane ofthe internal surface 346 and 20° inclusive in this embodiment, to createthe taper of the annular portion 340 b. The external surface 347 isgenerally flat. Connecting the external surface 347 to the externalsurface 343 is a first rear surface 348 of the olive 340. Connecting theinternal surface 346 to the external surface 347 is a second rearsurface 349 of the olive 340. The first rear surface 348 and the secondrear surface 349 both project in a substantially perpendicular directionto the longitudinal axis of the olive 340. The first rear surface 348and the second rear surface 349 are both flat surfaces in thisembodiment.

In this embodiment, the assembly 300 further includes a resilient washer350, with an appropriate internal diameter such that a washer 350 fitson each pipe 302 with a very small clearance, e.g. in this embodiment,the internal diameter is 113 mm. Referring now to FIGS. 20A to 20C, thewasher 350 is a spring washer. The washer 350 is annular, with agenerally ‘b/p shaped’ cross section. It has a front surface 352 and arear surface 354. The front surface 352 and the rear surface 354 areconnected by two substantially curved transitions. At the radially outeredge of the washer 350, the front surface 352 is connected to the rearsurface 354 by a first curved transition 358 that defines the outerdiameter of the washer. Looking in cross-section, the curved transition356 is made up of a flat surface 356 b, and two curved surfaces, 356 aand 356 c. The flat surface 356 b is perpendicular to the front surface352 and the rear surface 354. The flat surface 356 b is 1 mm long inthis embodiment. Connecting the flat surface 356 b to the front surface352 is the curved surface 356 a. Connecting the flat surface 356 b tothe rear surface 354 is the curved surface 356 c. The curved surfaces356 a and 356 c are both convex, and have a radius of 0.5 mm in thisembodiment. At the radially inner edge of the washer 350, the frontsurface 352 is connected to the rear surface 354 by a second curvedtransition 358 that defines the inner diameter of the washer. Looking incross-section, the curved transition 358 is made up of two flatsurfaces, 358 b and 358 d, and four curved surfaces 358 a, 358 c, 358 e,and 358 f. The flat surface 358 b is perpendicular to the front surface352 and the rear surface 354. The flat surface 358 b is 0.2 mm long inthis embodiment. The flat surface 358 d is parallel to the front surface352 and the rear surface 354. The flat surface 358 d is 1.2 mm long inthis embodiment. Connecting the flat surface 358 b to the front surface352 is the curved surface 358 a. Connecting the flat surface 358 b tothe flat surface 358 d is the curved surface 358 c. The curved surfaces358 a and 358 c are both convex, and have a radius of 1.9 mm in thisembodiment. Connecting the flat surface 358 d to the rear surface 354are two curved surfaces, 358 e and 358 f. The curved surface 358 e isadjacent the flat surface 358 d and is convex, with a radius of 1.5 mmin this embodiment. The curved surface 358 f is adjacent the rearsurface 354 and is convex, with a radius of 0.5 mm in this embodiment.The washer 350 is typically made of metal, such as steel. Preferably asprung steel will be used, with a high yield strength and high elasticmodulus, such as medium/high carbon-steel, but any suitable material canbe used. It will also be appreciated that any suitable type of resilientwasher may be used. It will be appreciated that the ‘springiness’ shapeis a function of both the described geometrical shape of the washer andthe material the washer is made from.

To assemble the components of the assembly 300, firstly the free end ofeach pipe 302 is machined to form the machined portions 308, and thegrooves 309 in the appropriate places on the pipes 302. Then, takingeach pipe 302 individually, the washer 350 is slid on to the free end ofthe pipe 302. The olive 340 is then slid on to the free end of the pipe302. The sleeve 330 is slid on to the pipe 302 next. At this point, thetwo pipes 302 are brought together, such that the sleeve 330 bridges thegap between the pipes.

The two halves 310 a, 310 b of the connector body 310 are brought aroundthe pipes 302, the sleeve 330, the olives 340, and the washer 350. Theprojections 314 of the connector body 310 correspond with the grooves309, so engage the grooves 309 of the pipes 302, to prevent or limitaxial movement of the connector body 310 relative to the free end of thepipes 302. The washer 350 and the olive 340 are accommodated within thechannel 316. The washer 350 is dimensioned to have an internal diametersimilar to the external diameter of the pipe 302 and an externaldiameter similar to the bore of the internal surface 316 c. Therefore,the washer 350 fits in the channel 316 and contacts the front surface316 a of the channel 316. The front surface 344 of the annular portion340 a of the olive 340 contacts the washer 350. The washer 350 isarranged such that the curved transition 358 of the washer 350 abuts thefront surface 344 of the olive 340 in use. This enables the washer todeflect to sustain any force that is applied and substantially limit themovement of the olive 340.

To couple the first and second halves 310 a, 310 b of the connector body310, connecting members are threaded through the apertures 322. Forexample, a plurality of threaded bolts (not shown) could be used. Thebody of the bolt will pass through the void created by the groove 326,and the bore 322 a, of the aperture 322 and the head of the bolt willengage the annular surface 324. The body of the bolt will protrude fromthe opposing open end of the aperture 322 where a nut can be threaded onthe body of the bolt. This substantially secures the first and secondhalves 310 a, 310 b of the connector body from relative movement in atransverse or longitudinal direction.

A plurality of bolts (not shown) are then inserted through the apertures328 from the front surface 312 a in the direction of the channel 316 ofthe connector body 310. They pass through the channels 329 and contactthe washer 350, which is located adjacent the openings of the channels329 in the surface 316 a, as shown most clearly in FIG. 15. The boltsmay have an external thread and the channels 329 may have an internalthread. As the bolts are tightened, a force is therefore applied to thewasher 350 and is transferred to the olive 340. The washer 350advantageously ensures that the force applied is maintained in use, asit can account for any natural ‘flex’ that may occur, as well as anydecrease in the force applied by bolts over time, or if they loosen inuse. It also protects the olive 340 from abrasive damage from the bolts.

The force applied by the bolts acts on the olive 340 in the direction ofthe sleeve 330. Specifically, the angled surface 347 of the olive 340engages the angled surface 332 b of the sleeve 330. The angled surfacesinterface and the olive 340 conforms to the greater angle of the surface332 b of the sleeve 330. This creates a strong mechanical seal betweenthe sleeve 330 and the olive 340.

Therefore, in use, oil can pass from one pipe 302 to another pipe 302under high pressure with a very low risk of leakage due to the strongmechanical seal created by the assembly 300.

Referring now to FIGS. 21 and 22, a coupling arrangement is indicatedgenerally at 400. The coupling arrangement 400 utilises the samemechanical seal arrangement 406 as described for the previousembodiments, except the connector body (110 of the previous embodiment)is now a connector 410 having a female open end configured to receive amale free end of a pipe 402. The connector 410 can be any type ofconnector that is configured to receive a pipe, such as a general pipejoint, a flexible connection, a valve, or a pipe reducer. The skilledperson will appreciate any other appropriate applications of thecoupling arrangement 400.

The connector 410 has an open end that receives the pipe 402. The pipe402 includes a circumferential groove 409. In this embodiment theconnector 410 has a radial internal surface 412 that engages the freeend of the pipe 402. The radial internal surface 412 provides a stop forthe pipe 402 when it is inserted into the open end of the connector 410during assembly of the coupling arrangement 400.

The connector 410 also includes an internal angled surface 414. Theangled surface 414 is equivalent to the surface portion 132 b of thefirst embodiment, and is intended to engage a corresponding angledsurface of an olive 450 to create a metal-to-metal seal (described inmore detail below). The angled surface 414 has an angle of approximately12° to the longitudinal axis of the connector 410, and 24° inclusive inthis embodiment.

The connector 410 also includes a circumferential groove 416, withdimensions that are equivalent to the groove 409 of the pipe 402.

Axial movement of the connector 410 relative to the pipe 402 issubstantially prevented or limited by a mechanical interlockarrangement. In this embodiment, a cap 430 encircles a portion of thepipe 402 and the connector 410 to help prevent separation of the pipe402 and the connector 410 in use. As shown most clearly in FIG. 22, thecap 430 has a constant external diameter but a varying internal diametersuch that three portions of the cap are defined. Starting from the leftin FIG. 22, the first portion 430 a has an internal diametersubstantially equal to the external diameter of the pipe 402 such thatthe cap fits over the pipe 402 with a small clearance. The secondportion 430 b has a greater internal diameter 430 b such that a cavity432 is defined between the external surface of the pipe 402 and theinternal surface of the second cap portion 430 b. The cavity 432 isdimensioned such that it can house an olive 440 and a washer 450 of themechanical seal arrangement 406 (described in more detail below). Thethird portion 430 c has an internal diameter substantially equal to theexternal diameter of the connector 410 such that the cap 430 fits overthe connector 410 with a small clearance.

A circumferential projection 434 projects from the internal surface ofthe first cap portion 430 a. The projection 434 corresponds to thegroove 409 in the pipe 402, such that the projection 434 and the groove409 engage in use, substantially preventing relative axial movement. Acircumferential projection 436 also projects from the internal surfaceof the third cap portion 430 c. The projection 436 corresponds to thegroove 416 in the connector 410, such that the projection 436 and thegroove 416 engage in use, substantially preventing relative axialmovement. It will be appreciated that other methods of substantiallypreventing relative axial movement could be used. For example,corresponding threaded surfaces could be provided, e.g. such that thecap is ‘screwed’ on during assembly. A front surface 438 of the cap 430includes a plurality of apertures 439 that pass through the entire depthof the first cap portion 430 a, from the front surface 438 to the cavity432, such that openings are provided into the cavity 432 that aresubstantially adjacent the olive 440 and the washer 450 in use. Theapertures 439 are equivalent to the circular apertures 328 of theprevious embodiment, and will be not be described in any more detail.

The cap 430 is split in two halves along a horizontal plane (not shownin Figures), equivalent to the split of the connector body 110 of thefirst embodiment. This enables the two halves of the cap 430 to bebrought together to encircle a portion of the pipe 402 and a portion ofthe connector 410 during assembly of the coupling arrangement 400. Itcan be seen from FIG. 23 that a plurality of apertures 433 are includedin the external surface of the cap 430 to enable the two halves of thecap 430 to be secured together in an equivalent way to how the twohalves of the connector body 310 are secured together in the firstembodiment.

The olive 440 and washer 450 are as described in the first embodimentherein.

To assemble the coupling arrangement 400, the grooves 409, 416 are madein the pipe 402 and the connector 410 respectively. The pipe 402 is thenslid inside the open end of the connector 410 such that the free end ofthe pipe 402 engages the radial internal surface 412 of the connector410. The olive 440 is then slid on to the pipe 402, such that the angledsurface of the tapered portion of the olive 440 engages the angledsurface 414 of the connector 410. The washer 450 is then slid on to thepipe 402. The two halves of the cap 430 are brought together around thepipe 402 and the connector 410, and connecting members are threadedthrough the apertures 433. The projections 434, 436 engage the grooves409, 416 respectively. The olive 440 and the washer 450 are receivedwithin the cavity 432 of the cap 430.

A plurality of bolts (not shown) are then inserted through the apertures439 from the front surface 438 in the direction of the cavity 432 of thecap 430. They pass through channels in the first cap portion 430 a andcontact the washer 450, which is located adjacent the openings in afront surface 432 a of the cavity. The bolts may have an external threadand the channels may have an internal thread. As the bolts aretightened, a force is therefore applied to the washer 450 and istransferred to the olive 440.

The force applied by the bolts acts on the olive 440 in the direction ofthe connector 410. Specifically, an angled surface 447 of the olive 440engages the angled surface 414 of the connector 410. The angled surfacesinterface and the olive 440 conforms to the greater angle of the surface414 of the connector 410. This creates a strong mechanical seal betweenthe connector 410 and the olive 440.

Therefore, in use, fluid can pass from the pipe 402 to the connector 410under high pressure with a very low risk of leakage due to the strongmechanical seal created by the coupling assembly 400.

A further embodiment of the invention is shown in FIGS. 24 to 28.Features corresponding to those of the two previous embodiments havebeen given corresponding reference numbers with the additional prefix“5”. Only features that differ from those of the previous embodimentsare discussed in detail.

With reference to FIG. 24, a coupling arrangement is indicated generallyat 500. The coupling arrangement 500 utilises a similar mechanical sealarrangement 506 to that described in the previous embodiments. Theassembly 500 is discussed by way of example as connecting two pipes 502in fluid communication. However, the assembly 500 can also be used inconnecting a pipe to a connector in fluid communication.

With reference to FIG. 25, the connector body 510 of this embodimentcomprises a mechanical engagement arrangement 570 configured to parentor limit axial movement of the pipe 502 in relation to the connectorbody 510. The engagement arrangement 570 of this embodiment comprisestwo barbs saw teeth 511. The barbs 511 are circumferential and projectfrom an internal wall of the connector body 510. The barbs 511 of thisembodiment comprise a tapered ridge, with the taper increasing in heighttowards the connector body end proximal the free end of the pipe 502,for ease of assembly. The barbs 511 are hardened by some suitable methodto facilitate their engagement with the pipe 502.

In alternative embodiments the barbs 511 may be of some other suitableshape. In alternative embodiments, some other suitable number of barbsmay be provided, e.g. 1 barb or 3 or more barbs.

The barbs 511 are pressed into the pipe 502 by the force of bolts thatare used to connect the two parts of the connector body 510, and thusprevent or limit axial movement of the connector body 510 relative tothe pipe 502.

The barbs 511 provide an interference fit with the pipe 502, and removethe need for machining or welding of the pipe 502. Fitting of theconnector assembly 500 is thus simplified.

As shown in FIGS. 25, 26 a and 26 b, the olive of the previousembodiments is replaced in this embodiment with an annular seal element540. The seal element 540 comprises three annular portions 540 a, 540 band 540 c. In this embodiment the three annular portions 540 a, 540 b,540 c are integral to one another.

The base annular portion 540 a is generally rectangular in crosssection, i.e. an internal surface 542 and an external surface 543 of theannular portion 540 a are parallel. The annular portion 540 a has afront surface 544 that connects the internal surface 542 and theexternal surface 543. The front surface 544 provides a loading surfaceconfigured to, in use, receive the axial force provided by bolts (notshown).

Projecting in a generally perpendicular direction, i.e. coaxial to thelongitudinal axis of the pipe, from the front surface 544 is theintermediate annular portion 540 b. The intermediate portion 540 b isgenerally tapered, decreasing in width away from the front surface 544.The intermediate portion 540 b has a smaller external diameter than thebase portion 540 a. The intermediate portion 540 b of this embodimenthas a concave internal surface 546. Force is transmitted from theloading surface 544 via the intermediate portion 540 a to the contactportion 540 c.

The annular portion 540 b also has an external surface 547. The externalsurface 547 is angled, at approximately 10° to the longitudinal axis, tocreate the taper of the annular portion 540 b. The external surface 547is generally flat in profile.

The seal element 540 has an annular contact portion 540 c at the freeend of the intermediate portion 540 b. The contact portion 540 c isconfigured to provide a seal between the pipe 502 and the sleeve 530.The contact portion 540 c projects radially beyond the intermediateportion 540 b. In this embodiment, the contact portion 540 c projectsbeyond the intermediate portion 540 b in both radial directions. Inother embodiments (not shown), the contact portion 540 c may projectbeyond the intermediate portion 540 b in only one direction, i.e.radially inwardly or outwardly, or may project by different amounts inone or other direction.

In use, due to the projection of the contact portion 540 c, it is thecontact portion 540 c that conforms to and seals against the sleeve 530and the pipe 502 when an axial force is applied to the seal element 540by bolts (not shown). The contact portion 540 c contacts the pipe 502and the sleeve 530 in a predetermined annular deformation region ofrelatively thin circumferential lines. The radial force created throughthe axial force pushing the seal element 540 is applied on these twonarrow rings, creating maximum pressure at the point of sealing.

In this embodiment, the contact portion 540 c is substantially circularin cross-section, so that suitable sealing is created. In alternativeembodiments, some other suitable profile may be used, e.g. diamondshaped in profile with the vertices of a diamond shape projectingradially outwardly.

The concave profile of the intermediate portion 540 b allows thatportion 540 b to act with a predetermined degree of resilience and cantherefore flex to ensure that the contact portion 540 c creates thedesired annular seal with the pipe 502 and the sleeve 530 even if theyare out of round to some extent.

The seal element 540 of this embodiment can be used in place of theolive of any of the previous embodiments.

The seal element 540 of this embodiment is metallic. In alternativeembodiments, some other suitable material may be used.

In other embodiments, the base and intermediate portions of the sealelement may not be visually distinct from one another as in thisembodiment.

As can be seen in FIG. 25, no resilient washer is provided in thisembodiment between the seal element 540 and bolts that apply pressure tothe seal element 540. The resilience of the seal element 540 compensatesfor the washer. Such an arrangement may be used in the previousembodiments, or a resilient washer (not shown) may be used in thepresent embodiment.

With reference to FIGS. 24 and 27, the connector body 510 compriseshousing ends 510 c, 510 d and the sleeve 530. The housing of theconnector body 510 of this embodiment is substantially square in crosssection along the longitudinal axis. The connector body 510 defines acentral bore 560 configured to receive a pipe 502. As with the previousembodiments, the housing of the connector body 510 is manufactured intwo parts, and is split in two along the horizontal plane extending inthe direction of the longitudinal axis. In this embodiment, the housing510 is also split in two along the vertical plane perpendicular to thelongitudinal axis to form two parts or ends 510 c, 510 d. Each of theends 510 c, 510 d is split in two along the horizontal plane.

In this embodiment, the housing parts 510 c, 510 d and the sleeve 530bridges the free ends of the pipes 502. In alternative embodiments, notshown, the connector body 510 may be used to attach a pipe connection influid communication with the pipe 502, by serving to connect thatconnection with the sleeve 530 and a mechanical seal arrangement 506.

The square profile of the connector body 510 provides increasedstrength. In this embodiment, in each end 510 c, 510 d, 14 mm bolts (notshown) are used to connect the two halves 510 a, 510 b together,providing suitable strength to resist the bending forces created. Inother embodiments other suitable fasteners may be used.

As shown in FIG. 25, the central bore 560 of the connector body 510defines a circumferential projection 562 configured to locate the sleeve530 in relation to the connector body 510. To this end, the sleeve 530,as shown in FIG. 16, defines two circumferential grooves 564corresponding to the projection 562. Each groove 564 is configured toreceive the projection 562 of one connector body 510.

In this embodiment, the sleeve 530 defines a circumferential projection535 extending inwardly from the internal surface of the sleeve. Theprojection 535, is substantially rectangular in profile. The projection535 is centrally located along the longitudinal axis of the sleeve 530.The projection 535 is configured to extend into the chamfers at the freeends of the pipes 502.

Providing a part connector body 510 c, 510 d for each free end of a pipeor connector allows each connector body 510 c, 510 d to be lighter, andas such easier to fit. In addition, the connector body 510 c, 510 d canadvantageously be used for multiple purposes, i.e. for a pipe free endor some other connector as described above. For example, the connectorbody could be used in connecting such items as valves, T-pieces or pipebends without the need for welding.

The sleeve 530 of this or previous embodiments can be manufactured invarious lengths for different applications, to bridge gaps of differentsizes, and to act as a means of pipe repair.

The embodiments described above are suitable for use with fluids (i.e.liquids or gases) such as crude oil, natural gas, hydrocarbons, water orchemical injection, or other suitable fluids. By way of example, theembodiments described above are suitable for use at temperatures from270K to 394K, or other suitable temperatures.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiments,it is to be understood that the invention is not to be limited to thedisclosed embodiments, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

1. A metallic annular seal element for sealing a pipe joint, themetallic annular seal element having a ring-shaped body having alongitudinal axis and comprising a first longitudinal end and a secondlongitudinal end; the first longitudinal end comprising a base having aloading surface configured to receive an axial force when the metallicannular seal element is in use; the second longitudinal end comprising aseal portion configured to provide a seal between a pipe and asurrounding secondary object when the metallic annular seal element isin use, and the metallic annular seal element further comprising anintermediate portion located between the base and the seal portionconfigured to transmit axial force applied to the base when the metallicannular seal element is in use, wherein the intermediate portioncomprises an annular internal surface, configured to be proximal a pipewhen the metallic annular seal element is in use, and an annularexternal surface, configured to be distal said pipe when the metallicannular seal element is in use; further wherein the seal portionprojects radially beyond said annular internal surface and radiallybeyond said annular external surface.
 2. The metallic annular sealelement of claim 1, wherein the intermediate portion is resilientlydeformable so as to be capable of flexion under the application of aforce.
 3. The metallic annular seal element of claim 1, wherein saidannular internal surface has a concave profile.
 4. The metallic annularseal element of claim 1, wherein the intermediate portion has across-section which reduces from a first width proximal the base to asecond width proximal the seal portion.
 5. The metallic annular sealelement of claim 1, wherein said annular external surface is an angledsurface.
 6. The metallic annular seal element of claim 1, wherein theintermediate portion and the base each define an outer diameter, andwherein the outer diameter of the intermediate portion is less than theouter diameter of the base.
 7. The metallic annular seal element ofclaim 1, wherein the base is substantially rectangular in cross-section.8. The metallic annular seal element of claim 1, wherein the sealportion is substantially circular in cross-section.
 9. The metallicannular seal element of claim 1, wherein the seal portion is deformable.10. A metallic annular seal element for sealing a pipe joint, the sealelement comprising: a loading portion; an intermediate portion; and acontact portion; wherein the loading portion is configured to receive anaxial force and transmit said force via the intermediate portion to thecontact portion, and wherein the contact portion is configured toprovide a seal between the pipe and a surrounding secondary object; andwherein the contact portion is configured to project radially beyond theintermediate portion, so as to define an annular deformation region forconforming to said secondary object seal element or pipe uponapplication of a predetermined axial force via said loading portion. 11.The metallic annular seal element of claim 10, wherein the intermediateportion is resiliently deformable so as to be capable of flexion underthe application of a force.
 12. The metallic annular seal element ofclaim 10, wherein the contact portion is configured to project radiallyoutward beyond the intermediate portion.
 13. The metallic annular sealelement of claim 10, wherein the contact portion is configured toproject radially inward beyond the intermediate portion.
 14. Themetallic annular seal element of claim 10, wherein the contact portionis substantially circular in cross-section.
 15. The metallic annularseal element of claim 10, wherein the intermediate portion comprises aninternal surface.
 16. The metallic annular seal element of claim 10,wherein the intermediate portion is tapered towards the contact portion.17. The metallic annular seal element of claim 10, wherein theintermediate portion comprises an external surface, and wherein theexternal surface is an angled surface relative to a longitudinal axis ofthe metallic annular seal element.
 18. The annular seal element of claim17, wherein the external surface of the intermediate portion has anangle of inclination of 10° relative to said longitudinal axis.
 19. Theannular seal element of claim 10, wherein the intermediate portion andthe loading portion each comprise an external diameter, and wherein theexternal diameter of the intermediate portion is less than the externaldiameter of the loading portion.
 20. The annular seal element of claim10, wherein the loading portion is substantially rectangular incross-section.
 21. The metallic annular seal element of claim 15,wherein the internal surface has a concave profile.